NodeEditor and NodeEditor Plus have an Ellipse Center command, with an angle input. It's angle input is in degrees, with degrees internally converted to radians.
Ellipse Width, Height, and Angle, are converted to MoI Ellipse factory width point and height point, using the two radian values, with frame.evaluate(), and cosine and sine, (polar to cartesian).
So tilt angle would be in degrees.

A different Ellipse Center node, Ellipse CenterR node with radian angle inputs, might be desire-able.

- Brian